YEREVAN -- Opposition leader Levon Ter-Petrossian stepped up his criticism of Armenian attempts of rapprochement with Turkey at a rally on May 15, RFE/RL's Armenian Service reports.

Ter-Petrossian told a few thousand supporters that while the government has given up on insisting that Ankara admit to committing genocide against Armenians nearly 100 years ago and still hasn't got Turkey to open the border, "now [Turkey and the United States] are saying, 'Give up Nagorno-Karabakh and we will open the border.'"

Ter-Petrossian is the Armenian National Congress's (HAK) mayoral candidate in the May 31 municipal elections in Yerevan.

He said an HAK victory would mark an important milestone in his campaign to change "the existing kleptocratic system" in Armenia.

He warned Yerevan residents who do not support his alliance that they "will be accomplices of the malevolent authorities that have stepped onto the path of national treason."

Other speakers said that HAK's main challenge is to prevent massive vote rigging in the elections.

Pro-government pollsters are predicting the ruling Republican Party and its candidate, Yerevan Mayor Gagik Beglarian, will garner more than 50 percent of the vote.